/*
 * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
 * Copyright (C) 2009, Henon <meinrad.recheis@gmail.com>
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Git Development Community nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using System.Linq;
using System.Collections.Generic;

namespace GitSharp.Core.RevWalk
{
	/// <summary>
	/// Multiple application level mark bits for <see cref="RevObject"/>s.
	/// </summary>
	public class RevFlagSet : HashSet<RevFlag>
	{
		public int Mask { get; private set; }

		/// <summary>
		/// Create a set of flags.
		/// </summary>
		public RevFlagSet()
		{
		}

		/// <summary>
		/// Create a set of flags.
		/// </summary>
		/// <param name="flags">the set to copy flags from.</param>
		public RevFlagSet(RevFlagSet flags)
		{
			Mask = flags.Mask;
		}

		/// <summary>
		/// Create a set of flags.
		/// </summary>
		/// <param name="collection">the collection to copy flags from.</param>
		public RevFlagSet(IEnumerable<RevFlag> collection)
			: base(collection)
		{
      addAll();
    }

	  private void addAll()
	  {
	    foreach (var set in this)
	    {
	      Mask |= set.Mask;
	    }
	  }

	  public bool Equals(RevFlagSet other)
	  {
	    if (ReferenceEquals(null, other)) return false;
	    if (ReferenceEquals(this, other)) return true;
	    return other.Mask == Mask;
	  }

	  public override bool Equals(object obj)
	  {
	    if (ReferenceEquals(null, obj)) return false;
	    if (ReferenceEquals(this, obj)) return true;
	    if (obj.GetType() != typeof (RevFlagSet)) return false;
	    return Equals((RevFlagSet) obj);
	  }

	  public override int GetHashCode()
	  {
	    return Mask;
	  }

	  public static bool operator ==(RevFlagSet left, RevFlagSet right)
	  {
	    return Equals(left, right);
	  }

	  public static bool operator !=(RevFlagSet left, RevFlagSet right)
	  {
	    return !Equals(left, right);
	  }

	  public bool ContainsAll(IEnumerable<RevFlag> c) // [henon] was Collection<?> in java
		{
			RevFlagSet oFlag = (c as RevFlagSet);
			if (oFlag != null)
			{
				int cMask = oFlag.Mask;
				return (Mask & cMask) == cMask;
			}

			return c.All(flag => Contains(flag));
		}

		public new bool Add(RevFlag flag)
		{
			if ((Mask & flag.Mask) != 0)
			{
				return false;
			}

			Mask |= flag.Mask;

			int p = 0;
			foreach(var x in this)
			{
				if(x.Mask < flag.Mask)
				{
					p++;
				}
				else
				{
					break;
				}
			}

			return base.Add(flag);
		}

		public new bool Remove(RevFlag flag)
		{
			if ((Mask & flag.Mask) == 0)
			{
				return false;
			}
			
			Mask &= ~flag.Mask;

			return base.Remove(flag);
		}
	}
}